v3.26.1
FAIR VALUE MEASUREMENTS: Fair Value, by Balance Sheet Grouping (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Corporate Fixed-Income And Asset-Backed Debt Securities    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value $ 1,800 $ 1,400
Carrying Amount    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Receivable [1] 1,507 1,507
Held-to-maturity securities [1],[2] 34,119 33,822
Long-term debt [1] 3,794,116 3,447,338
Carrying Amount | Idaho Power Company    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Held-to-maturity securities [1],[2] 34,119 33,822
Long-term debt [1] 3,794,116 3,447,338
Estimated Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Receivable [1] 1,507 1,507
Held-to-maturity securities [1],[2] 32,315 32,468
Long-term debt [1] 3,565,887 3,270,200
Estimated Fair Value | Idaho Power Company    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Held-to-maturity securities [1],[2] 32,315 32,468
Long-term debt [1] $ 3,565,887 $ 3,270,200
[1]
(1) Notes receivable are categorized as Level 3 and held-to-maturity securities and long-term debt are categorized as Level 2 of the fair value hierarchy, as defined earlier in this Note 12 - "Fair Value Measurements."
[2]
(2) All held-to-maturity securities are carried at amortized cost and were in a gross unrealized holding loss position totaling $1.8 million and $1.4 million as of March 31, 2026, and December 31, 2025, respectively. Substantially all of these debt securities mature between 2027 and 2038. Based on ongoing credit evaluations of these holdings, Idaho Power does not expect payment defaults or delinquencies and had not recorded an allowance for credit losses for these securities as of March 31, 2026, and December 31, 2025.